Botez in U.S. Pat. No. 4,347,486, incorporated herein by reference, has disclosed a large optical cavity constricted double heterostructure semiconductor laser comprising a body of semiconductor material which includes a substrate with a pair of spaced apart channels in a major surface thereof with a mesa therebetween. A first confinement layer overlies the surface of the substrate, the mesa and the surfaces of the channels. A light propagation region composed of an active layer and an adjacent guide layer overlies the first confinement layer and a second confinement layer overlies the active layer. The active layer is the recombination region of the laser with laser light generated therein. The light beam so generated propagates in both the thin active layer and, primarily, in the relatively thicker guide layer. This laser has excellent selectivity against lasing of higher order modes of the structure since the waveguide formed by the light propagation region in the lateral direction (the direction in the plane of the layers and perpendicular to the axis of the channels) exhibits high loss for these modes.
We have found, however, that the manufacturing yield of such lasers fabricated from a wafer is very low. It would be desirable to have a laser structure which has a high manufacturing yield to minimize the cost of such devices.